Admin dashboard v2

[nathanielrindlaub]

Add created field to Projects + admin dashboard project editing support

Summary

Adds a created timestamp field to Project documents and extends updateProject to support editing timezone and availableMLModels for superusers, in support of an admin dashboard v2.

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Changes

New Project.created field

• Added created: Date to the Mongoose ProjectSchema with default: Date.now, so all new projects automatically record their creation timestamp.
• Exposed created: Date! on the Project GraphQL type.

updateProject improvements

• Added protection for the default_project — it can no longer be edited via this mutation.
• Superuser-only: timezone and availableMLModels can now be set via UpdateProjectInput, but only by superusers. Non-superusers receive a ForbiddenError.
• Additive-only availableMLModels: incoming model IDs are merged (union) with the existing array — models can only be added, never removed, to prevent unexpected downstream consequences. New model IDs are validated against the database before being accepted.

Backfill migration

• Added backfill-project-created operation to operations.js that derives each existing project's created date from the ObjectId timestamp of its default "All images" view. Falls back to new Date() (with a warning) if no such view is found.

⚠️ Pre-deploy requirement: The backfill-project-created migration must be run against each environment before this deploy. Until it runs, existing project documents lack created, and any save() on those documents will fail Mongoose's required validation.